Spark plug



DEQ.

N. H. RUSSELL SPARK PLUG Fild De. 16 1920 Nachanal H. Huelga EU.

S14/vento@ Patented Der. 16, 1924. I

NATHANIFJ. n. RUSSELL, or cHIcAGo, uLrNoIs.

SPARK PLUG.

Application filed December 16, 1920. Serial No. 431,206.

To aZZ whom it may concern.

'Be it known thatI, NATHANIEL H. RussELL, a citizen of the United States, residing at Chicago, in the county of Cook and Statel of Illinois, have invented certain new and useful Improvements in Spark Plugs, of

which the following is a specification. ,l

This invention relates to spark plugs, and

1s an improvement on my pending appli- @ation sled Jan. 12, 1920,`seria1 #350,s9,1, and the primary objectbf the present in-v vention is to produce a spark plug, in which the short circuiting of the electrical conductors thereof by moisture or other external means is prevented, so constructed that anl exceptionally simple structure will be presented embodying a minimum number of tion, in

parts. l

Another object of the invention is to provide a protecting housing for the upper end of a spark plug, so as to prevent vthe short circuiting of the electrical conductors thereof, and to form a guard for the. porcelain or insulating body, so as to prevent the same from becoming broken" by external blows.

A further object of the'invention is to provide a housing embodying a packing gland for the reception of the high tension lead wire of the plug, said packing gland also forming friction means for engaging said wire to prevent the accidental displacement thereof from the plug terminal, the gland also being located in the .same plane as the protecting housing, so as to eliminate all projecting parts on the fplug, whereby Vthe plug can be conveniently tted in all types of cylinder heads.

With these and other objects in view, the invention consists in the novel construction, arrangement,.and formation of parts -aswill be hereinafter more specifically described,

claimed and illustrated in the accompanylng drawing, forming a part of this specificawhich drawing: v o iFlgure 1 is a l'side elevation of the improved spark plug, and

Y Figure 2 is a vertical longitudinal section through the same. Y

Referring to the drawings in detail,

wherein similar reference characters designate corresponding parts throughout the several views, the letter A indicates the shell of the spark plug, B, the porcelain or other insulating core thereof, and C, the protecting housing for the insulator core B and the high tension lead wire D.

The shell A may be of the usual or any preferred shape or configuration, and is preferably formed of steel or the like', and includes the cylindrical body 5, provided with the external thread 6, vfor permitting the shell to. be threaded into a cylinder head. The upper end of the cylindrical body 5 is provided with anenlarged polygonal extension 7 which forms means for permitting the shell to be engaged by a wrench or the like, so that the shell can be conveniently` i threaded into or out 'of engagement with a cylinder head. The enlarged polygonal extension 7 defines an internal shoulder 8, the

purpose of which-will also be hereinafter more fully described. n n

y The core B may also be of the usual orv any preferred construct-ion or shape and made from some insulating material, such as porcelain or the like, and the core as Yshown includes a cylindrical porcelain body 9 having its extreme lower end tapered, as at 10, for facilitating the insertion thereof into the shell A. A portion of the body 9 intermediate its ends is provided with an enlarged cylindrical portion 11, which forms upper and lower shoulders 12 and 13. The

shoulder 13 is adapted to sit upon the shoull der' 8 formed by the enlarged polygonal ex-l tension 7 of the cylindrical body 5. If so desired a suitable shock -absorbing packing gasket 14 may be interposed between lthe shoulders 13 and 8, so as to prevent any fracture of the porcelain byl cominginto intimate contact with the steel shell. The core B is provided with an axial longitudinally extending way 15 for the reception of the central electrode 16' which extends beyond the lowerv end lof the core and out lof the shell A. The upper and lower ends of the core B is provided with inwardly extending bore enlargements 17 and 18, and an annular fiange y19 is formed on the central electrode for engagement with the inner wall formed by the enlarged lower portion l 18 of the bore 15,- The lower end of the shell A-carries the inwardly extending right angularly bent electrode 20, the lower end of which terminates below a central electrode 16. This electrode 20 may be held in place against accidental displacement in the shell 6 by means of a struck-in portion 21. formedr in the main shell. The upper end of Vthe electrode 16 is screw threaded, as at 22, for

the reception of the retaining nut 23, which;

corv

engages-i111@ me? Wall of the enlarged porplace in the shell tion 17 of the bore 15. The threaded end 22 of the vcentral electrode 16 is also adapted to receive the connector 24 for the lead wire D which extends from the distributor (not shown). This connector 24 includes the internally threaded portion, which receives the upper threaded end of the central electrode 16, and the inner exposed end of the wire D. This connector is provided with a struck in portion 25, so-as to firmly engage the exposed end of the wire D, so as to prevent the pulling out of the wire from the connector 24.

The housing Cconstitutes the main part f of the invention and this housing includes a cylindrical hollow body 26, which is adapted to receive the upper end of the porcelain body, which projects outwardly from the shell A. lThe lower end of the hollow cvlin-.

drical body 26 is provided with external threads 27, for engaging the internal threads formed on the upper end of the polygonal enlarged portion 7 of the cylindrical body 5. The extreme lower end of the cylindrical hollow body 26 is adapted to engage the upper shoulder 12, formed by the enlarged portion 11 of the core B, and the housing forms means for holding the core B in A, and takes the place of the usual bushing. If so desired, a suitable flexible gasket 28 may be inserted between the shoulder 12 and the lower end of the hollow cylindrical body 26. The extreme upper end of the body 26 above the core B is provided with a packing gland 29, which has a bore 30, through which the wire D is adapted to extend. The outer end of the packing gland is provided with internal threads 31 for the reception of a gland bushing 32. This gland bushing 32 is provided with a bore 33 for the reception of the wire D, and a suitable gasket 34 is arranged around the wire D thebushing 32 is adapted to force the packing or gasket into tight engagement/'with the wire so as to prevent the seeping of moisture by the same. Thispacking not only forms a fluid or moisture proof joint,-

but also forms a means for frictionally en- `raging the wire so as to prev/ent the accidental withdrawing thereof from the housin(T C Changes in details may be made without departing from the spirit or scope of this invention: but,

l claim:

1. A spark plug comprising in combination a metallic shell. a body of insulation arranged in the shell and projecting outwardlv from one end thereof, an electrode carried by the body'of insulation. an electrode carried by the shell, a metallic housing carried by the shell, enveloping the upper end of the body of insulation and includino: a cylindrical body and an integral head formed on the upper end of the body overon the upper end of within the flange, and

lying the upper end of the body of insulation, a packing gland carried by thehead and disposed in direct alignment with said electrode carried by thel insulating body, and an electric insulated conductor wire extended through said packing gland and conductively connected to said insulated body carried electrode.

2. A spark plug comprising in combination a shell having an annular internal shoulder formed therein, a body of insulation fitted shoulder arranged to fit on said shoulder formed on said shell, the body of insulation projecting outwardly from the upper end of the shell, a central the body of insulation, an electrode carried in said shell havingan annular electrode carried by by the shell."a housing forreceiving and I enveloping the upper end of said body of insulation adjustably carried by the shell and arranged to engage the upper edge of said shoulder formed on the bod of insulation for urging thebody of insu ation into engagement with the shoulder formed on said shell, a head formed on the upper end of said housing, said head having an opening formed therein in direct alignment with said electrode, an insulated conductor wire extended through the head and opening.

means .connecting the wire to said central electrode. a., packing arranged in said head about said wire, means carried by. said head for compressing said packing into frictional engagement with said wire.

3. A spark plug comprising in combination a shell including a cylindrical body. and an enlarged polygolal portion formed sai nally extending body of insulation arranged in said shell having an annular enlargement formed thereon, the lower end of said enlargement adap'ted to seat on the shoulder formed by the enlarged polygonal portion of the shell, a housing detachablyf and ad- `iustably carried by the, envelop the upper end of the body of insulation. the upper and lower ends of the body of insulation having recesses formed therein. a packing gland carried by the upper end of the housing, a conductor insulated wire fitted into said packing gland, a centrallv disposed electrode carried by the body of insulation having one end thereof projecting outwardly from thebody of insulation and its other end arranged within the recess formed in the body of insulation, an electrode carried bv the shell.I the portion of said central electrode arranged in said recess being externally screw threaded. a wire connector carried by the inner end of the conductor insulated wire and threaded on sai-d threaded portion of the central electrode.

4. A spark plug comprising in\combina tion an insulating body having a longitudibody, a longitudi- Y shell arranged to www? nelly extending Wa therethrough, an electrode fitted in said way, a shell receiving the lower end of said insulator, a housing receiving the upper end of said insulator and connected to Saidshell, a packing gland carried b v the upper end of the housing arranged in alignment with said electrode, said gland having a packing therein, an insulated conductor Wire extended through said gland and pecking., and connected to l@ the upper end of said electrode, a bushing threaded into said ange into engagement with said packing, the Wire being extended through said bushing, and an electrode carried by" the shell andv arranged in close 15 proximity tofsaid'lcentral electrode.

NATHANEEL H. RUSSELL. 

